The present invention relates to a piston or rod seal comprising a scraper ring made of a PTFE material and supported in an open first groove, the latter being disposed radially with respect to a relatively moving machine part. An O-ring made of an elastomeric material and disposed on the bottom of this first groove presses the scraper ring against the machine part. On its side facing the piston or rod, the scraper ring has at least two sealing lips separated by a second groove. These sealing lips contact the piston rod with sealing edges, and on their side facing the O-ring, they have conical surfaces with an external diameter which axially increases in the direction toward the side facing away from the pressure.
A piston rod of this type is known from the German Patent Publication No. DE-OS 36 03 669. The sealing action achieved therewith is less than satisfactory, especially over long-term use.